MIMEBlackbox includes the components and functions, related to MIME (internet mail).

MIMEBlackbox includes classes that let you compose the e-mail message and optionally encrypt or sign it using X.509 certificates or OpenPGP keys.
You can parse and decrypt and verify the signature of the existing MIME e-mails too.

Also with MIMEBlackbox you can sign and verify signatures of the e-mail message using DKIM (DomainKeys Identified Mail) technology, used to help fighting spam.